The proposed Manchester RL side was planned for the White City Stadium - just up the road from Old Trafford if you're heading towards Manchester.
There were a few professional baseball leagues in the UK in the 1930's with quite a few teams in what is now Greater Manchester. Salford Reds were one of them - not sure about the 1950's, maybe they continued after the war as an amateur side or another team took on the same name. I think the 1930's Salford Reds played at the Willows (think I've got the info somewhere, will dig it out at some point),they may have been owned by the RL side.

I can confirm that the 1930's Salford Reds baseball club was owned by Salford RLFC and did play at the Willows. Several of the players were RL players and they drew crowds - at least in the first season of 1935 - over 3000. The semi-pro circuit lasted in England up until the outbreak of war, I'm not sure if Salford lasted to 1939 or not

No, it is not. Names based on the colour of the shirt that the team wore e.g. tigers, wasps, harlequins, all blacks go back to the early 19th century in both codes of rugby and in soccer as well e.g. the hoops = QPR.

I don't remember any Warriors / Crusaders / Vikings / Braves in British sport until the Super League era.

That doesn't necessarily make them a bad thing but they are an import.

I have the impression that there was always a race to just have the name of the town/city as that may have been prestigious with other local clubs using suffixes to distinguish from the rest.

That's about the strength of it. The strongest club in the city usually grabbed the [City Name] Football Club tag and other clubs had to make do with the name of a district or add a moniker like Rovers / City / United / Hornets.

just being pedantic tather than adding to the discussion (but hey, this is the internet!) but there's a football team in Northern Ireland called Crusaders (est.1898).
ps - whilst checking when they were formed I noted that they're nicknamed 'the hatchetmen'. A team from Belfast with a nickname like that, worrying ;-)

No, it is not. Names based on the colour of the shirt that the team wore e.g. tigers, wasps, harlequins, all blacks go back to the early 19th century in both codes of rugby and in soccer as well e.g. the hoops = QPR.

I don't remember any Warriors / Crusaders / Vikings / Braves in British sport until the Super League era.

That doesn't necessarily make them a bad thing but they are an import.